It's more the critical viscosity that will change under more extreme temperatures in a mineral oil... unlike a synthetic that is designed to cope with certain conditions. This is the main difference. I'd assume different synthetics and different mineral oils will have different capabilities in heat dissipation thus it is required to test many, both mineral and synthetic. The problem is though, the higher the temperature, the more of a need for a synthetic. You would eventually get to a point where a synthetic would be your only option. So my advise would be to use the manual for your bike to select the correct oil. An expensive synthetic wont use its capabilities, a mineral probably doesn't have the capabilities required but a semi synthetic, designed for your bike, will have the right mix. :)
Yes, with higher viscosity I expect the synthetic to shed more heat thus run cooler. Few degrees? I`m just thinking, you know. There is also a disturbing fact from Mercedes vehicles, they only approve certain synthetic oils to be used, minerals void the warranty, just any climate. I`m still processing that, what`s their point (other than blatant commercialism).
theoverengineer Mercedes may approve certain synthetic oils where they know the oil's specified range works with the engine requirements... with commercialism being a factor too. I'm still interested to see your results though. My bike can only take a semi as the clutch begins to slip with a fully synthetic and a mineral can't stand up to the demands of the engine.
Allan White Big factor, yes. Any oil in the bike should be JASO rated or equivalent to work with the friction plates in the clutch, fully synthetics are available, motorcycle dealers carry them. Synthetic vs. Mineral Oil test results
+mark prescott Combustion generates a fixed amount of heat, when heat is subtracted faster or more efficiently, an insulator or heat sink body of oil shouldn`t be in the way, storing the removed heat because it will re-introduce it to the engine. It`s like you can`t cool down fast on hot summer`s day by taking a steamy hot bath. You take a cold one.
+mark prescott Good point. Time is a factor, but both oils get circulated at the same speed, spending the same time inside the passages in the block. The difference between the 2 liquids are their specific heat capacities. Somewhat like comparing a cup of water and a piece of steel, both exactly the same size and shape. Starting at 90 degrees, they cool to room temperature. Steel will cool 9 times faster. By the time steel`s temperature has stabilized , water will be at about 80 degrees.
Its said synthetic flows quicker if true speed it a factor. Molicules are closer in steel therefor heat disperse at a quicker rate . water has hydrogen in it.that may help in keeping heat in.
+mark prescott It`s not the hydrogen, it`s the hydrogen bond between water molecules that store energy. Closeness of molecules is one of the factors, but not all. Atoms in steel are bigger and closer than in diamond, yet diamond is 10 times harder but 10% worse in heat dissipation. The specific heat capacity figures tell all about cooling/heating efficiency. Good discussion, thanks for watching and sharing thoughts.
